1. Field of the Invention
The present invention relates to a substrate inspection apparatus, a substrate inspection method and a semiconductor device manufacturing method, and is directed to, for example, a substrate inspection and a pattern measurement using an electron beam.
2. Related Background Art
In inspections and pattern measurements of semiconductor wafers, as the design rules are becoming finer in recent years, there is an increased need for inspections and measurements using an electron beam, which is favorable in high-resolution inspections.
Since a wafer surface is electrically charged in some manner, an electron beam-used substrate inspection has a problem in that non-uniformity occurs in the amount of at least any of secondary electrons, reflected electrons and backscattered electrons (hereinafter, simply referred to as “secondary electrons, etc.”) generated on the wafer surface as a result of irradiation with electron beam that can reach a detector, causing distortion, blurring or shading in the inspection image of a pattern (for example, see Japanese Patent Laid-Open No. 11 (1999)-326247, paragraphs [0006] to [0011], and FIGS. 10 and 11). It also has a problem in that the amount of secondary electrons, etc., that can reach a detector is decreased due to distortion of the trajectory of the secondary electrons, etc., caused as a result of a potential gradient that is not parallel to the wafer surface locally occurring depending on the material and structure of the wafer surface layer, thereby lowering the inspection sensitivity and increasing errors in defect determination (for example, see Japanese Patent Laid-Open No. 2004-354084, paragraph [0005] and [0006], and FIGS. 15 and 16). These problems are especially pronounced in the field of inspection and measurement of patterns formed of insulating materials such as resists.